In semiconductor manufacture, packaging is the final operation that transforms a semiconductor substrate into a functional semiconductor component. Typically, the semiconductor substrate is in the form of a semiconductor die. Packaging provides protection for the semiconductor substrate, a signal transmission system for the integrated circuits on the semiconductor substrate, and external connection points for the component. In response to the demand for smaller, lighter and thinner consumer products, new semiconductor components and new packaging methods are being developed. The new components include high pin count single die packages, such as fine ball grid array (FBGA) packages, and multi dice packages, such as stacked packages and systems in a package (SIP).
In fabricating semiconductor components, it is sometimes necessary to provide interconnects which transmit signals from a circuit side of a semiconductor substrate to the backside of the semiconductor substrate. Interconnects which extend through the semiconductor substrate from the circuit side to the backside are sometimes referred to as through interconnects. Typically through interconnects comprise metal filled vias formed in the semiconductor substrate, which are configured to electrically connect the integrated circuits on the circuit side to elements on a backside of the semiconductor substrate.
As semiconductor components become smaller and have higher input/output configurations, semiconductor manufacturers must fabricate through interconnects with increasingly smaller sizes and pitches, but without compromising the performance and reliability of the signal transmission system. In addition, it is preferable for through interconnects to be capable of volume manufacture using equipment and techniques that are known in the art.